What will happen when a SpaceX rocket collides with the Moon?

What will be the outcome when a SpaceX rocket collides with the Moon?

The upper stage of a SpaceX Falcon 9 rocket is the component slated to strike the Moon.

Over millions of years, the Moon has endured countless impacts. Asteroids and meteors have sculpted its characteristic pockmarked surface and extensive network of craters. More recently, it has also experienced collisions from the intrepid probes and landers dispatched by Earth-based space agencies.

Now, on Wednesday, scientists anticipate the Moon will experience another collision, this time from a wayward SpaceX rocket traveling at approximately 2.43 kilometers per second, or about 5,400 mph.

According to NASA's Centre for Near-Earth Object Studies (CNEOS), the upper section of one of SpaceX's Falcon 9 rockets is set to "impact" the Moon on August 5th.

The U.S. space agency reached this conclusion after independent astronomers, utilizing public data, observed that a segment of the rocket from a January 2025 launch was on an accidental collision course with the Moon.

"There is no danger to Earth," stated spokesperson Jimi Russell. "NASA will continue to track the booster for training purposes, as well as later observe the impact site for scientific purposes."

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SpaceX launched this particular Falcon 9 rocket last year as part of a joint U.S. and Japanese mission to transport a pair of lunar landers and scientific equipment to the Moon.

A portion of the Falcon 9 is reusable and designed to return to Earth for subsequent missions. However, other parts of the rocket are shed in space and remain there, stuck in orbit unless they eventually collide with another celestial body.

The specific piece in question is the rocket's upper stage, which is roughly the size of a five-story building and has an Earth weight of at least 4,000 kg (8,800 lbs).

Astronomer Bill Gray, who first identified the trajectory, indicates that the object will land near the Einstein Crater, located on the sunlit side of the Moon visible from Earth. He predicts it will create a crater exceeding 17 meters (56 ft) in diameter.

The Moon's surface bears the marks of countless other impacts spanning millions of years.

The impending collision – predicted to occur at approximately 02:35 EDT (06:35 GMT) on Wednesday – is expected to captivate both amateur and professional astronomers.

"It's something really huge smashing into the Moon. It's not remotely dangerous, we can just watch the show," remarked Dr. Matt Bothwell, a public astronomer at the University of Cambridge.

"It's going to impact and it's going to send up a huge plume of dust, maybe 50km into the air or more, and that's going to spread sideways over time," Bothwell explained.

Given the Moon's lack of atmosphere and significantly weaker gravitational pull, the moment of impact will be "more impressive than any [similar] explosion on Earth," Bothwell stated.

Nothing will impede the object's speed, as Earth's atmosphere would, and nothing will prevent the estimated million kilograms of debris from rocketing into space.

While the impact will not be visible from Earth with the naked eye, individuals with access to a sophisticated telescope may be able to observe a flash emanating from the Moon's surface, Bothwell noted.

More significantly, Bothwell highlighted the educational potential of the impact. He said this event would offer a unique opportunity to study the consequences of an object striking the Moon.

Consequently, scientists are preparing to closely monitor the event.

Large telescopes in the Americas, along with NASA's Lunar Reconnaissance Orbiter and South Korea's Danuri probe, will track the flash, plume, and new crater. Additionally, a citizen-science project is recruiting enthusiastic amateurs to film the impact.

By capturing the dust plume in action, astronomers hope to transform this accidental crash into a valuable experiment.

Observing the amount of material ejected, its altitude, and its subsequent descent should refine their models of lunar impacts – and even provide clues about what lies just beneath the surface at the impact site, where fresh subsurface material will be exposed for the first time.

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Bothwell, the astronomer, also suggested that the collision would serve as a cautionary tale regarding the escalating problem of human-made space debris.

"I think more people should be more worried about space debris," Bothwell asserted. "Every single year we put more stuff in orbit. Sometimes the satellites just collide, and they shatter into more pieces. I think there's a worry about a runaway cascade, if we put so much stuff in orbit."

According to the European Space Agency (ESA), approximately 54,000 objects larger than 10 cm are currently floating in space. In total, humans have launched about 17,000 tonnes of objects into space since the dawn of the Space Age in 1957.

The last dead rocket to impact the Moon was in 2022, when the Chinese Long March 3C upper stage from the 2014 Chang'e 5-T1 mission struck the far side of the Moon – the side facing away from Earth.

Decades earlier, NASA intentionally launched objects into the Moon to gather data for the Apollo missions.

*Additional reporting by Pallab Ghosh*